Brief Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Biol Chem. Jul 26, 2012; 3(7): 159-166
Published online Jul 26, 2012. doi: 10.4331/wjbc.v3.i7.159
Lipopolysaccharide triggers nuclear import of Lpcat1 to regulate inducible gene expression in lung epithelia
Bryon Ellis, Leah Kaercher, Courtney Snavely, Yutong Zhao, Chunbin Zou
Bryon Ellis, Leah Kaercher, Courtney Snavely, Yutong Zhao, Chunbin Zou, Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, United States
Author contributions: Zou C conceived the idea, designed the experiments, conducted subcellular fractionation, analyzed the data, supervised the experiments, and wrote the paper; Ellis B, Kaercher L, and Snavely C performed QRT-PCR; Zhao Y designed the primers.
Supported by A United States National Institutes of Health R01 grant HL091916 to Zhao Y and an American Heart Association grant 12SDG12040330 to Zou C, in part
Correspondence to: Dr. Chunbin Zou, Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, BST W1200, 200 Lothrop Street, Pittsburgh, PA 15213, United States. zouc@upmc.edu
Telephone: +1-412-6243666 Fax: +1-412-6243451
Received: December 11, 2011
Revised: February 10, 2012
Accepted: February 17, 2012
Published online: July 26, 2012
Abstract

AIM: To report that Lpcat1 plays an important role in regulating lipopolysaccharide (LPS) inducible gene transcription.

METHODS: Gene expression in Murine Lung Epithelial MLE-12 cells with LPS treatment or Haemophilus influenza and Escherichia coli infection was analyzed by employing quantitative Reverse Transcription Polymerase Chain Reaction techniques. Nucleofection was used to deliver Lenti-viral system to express or knock down Lpcat1 in MLE cells. Subcellular protein fractionation and Western blotting were utilized to study Lpcat1 nuclear relocation.

RESULTS: Lpcat1 translocates into the nucleus from the cytoplasm in murine lung epithelia (MLE) after LPS treatment. Haemophilus influenza and Escherichia coli, two LPS-containing pathogens that cause pneumonia, triggered Lpcat1 nuclear translocation from the cytoplasm. The LPS inducible gene expression profile was determined by quantitative reverse transcription polymerase chain reaction after silencing Lpcat1 or overexpression of the enzyme in MLE cells. We detected that 17 out of a total 38 screened genes were upregulated, 14 genes were suppressed, and 7 genes remained unchanged in LPS treated cells in comparison to controls. Knockdown of Lpcat1 by shRNA dramatically changed the spectrum of the LPS inducible gene transcription, as 18 genes out of 38 genes were upregulated, of which 20 genes were suppressed or unchanged. Notably, in Lpcat1 overexpressed cells, 25 genes out of 38 genes were reduced in the setting of LPS treatment.

CONCLUSION: These observations suggest that Lpcat1 relocates into the nucleus in response to bacterial infection to differentially regulate gene transcriptional repression.

Keywords: Lipopolysaccharide; Nuclear import; Lysophosphatidylcholine acyltransferase 1; Gene expression; Lung epithelia; Epigenetic code; Quantitative reverse transcription polymerase chain reaction; Haemophilus influenza; Escherichia coli